Methods and apparatus for three-dimensional nonvolatile memory

A method is provided that includes forming a word line above a substrate, forming a bit line above the substrate, forming a nonvolatile memory material between the word line and the bit line, the nonvolatile memory material including a semiconductor material layer and a conductive oxide material layer, forming a barrier material layer between the semiconductor material layer and the conductive oxide material layer, and forming a memory cell including the nonvolatile memory material at an intersection of the bit line and the word line. The word line is disposed in a first direction, the bit line is disposed in a second direction perpendicular to the first direction. The barrier material layer has an ionic conductivity of greater than about 0.1 Siemens/cm @ 1000° C.